Figure shows (only cross section) a wooden cylinder C with a mass m of 0.25Kg. a radius R and a length l perpendicular to the plane of paper of 0.1 meter with N equal to 10 turns of wire wrapped around it longitudinally, so that the plane of the wire loop contains the axis of cylinder. What is the least current through the loop that will prevent the cylinder from rolling down a plane whose surface is inclined at angle θ to the horizontal, in the presence of a vertical field of magnetic induction 0.5 weber/meter2, if the plane of the windings is parallel to the inclined plane?
